Fut Sau means Buddha Hand.
Heres a couple of links to the Fut Sau Wing Chun.
The Fut Sau Wing Chun has some similarities with Bagua and other internal cultivation systems.
As for your initial question. The Fut Sau Wing Chun is Wing Chun(its unique) but their are hundreds of branches of Wing Chun some have closer similarities and some are more different. For instance Pao Fa Lien, Pan Nam, Chi Sim, Nanyang are generally different than the more common Ip Man system from its ancestry of Hung Suen.
Here are a few more links to check out.
Fut Sau Wing Chun or Fo Han Yong Chun